Flight testing is planned to begin in August and and the NAV is expected to be available for commercial sales from 2010.

Designed to operate outside in wind speeds of at least 13.6kt (25km/h) and offer an endurance that is "a significant fraction of an hour", the Prox Dynamics' Black Hornet PD-100 NAV helicopter will have a carbonfibre structure and use Chinese batteries that can be fully charged in 5min.

The first version will not be fully autonomous, and inside buldings will need manual input from a pilot via remote control. Its microelectronics and sensors will come from the model aircraft industry and its range is limited by the video link.

It has yet to be decided whether the vision system will help with guidance. A numerical model of the helicopter's fight envelope also has to be developed and the company says it already has secured $1 million of funding for the project.

News that Etihad's partner Air Berlin has followed stablemate Alitalia into a formal restructuring process on top of the Gulf carrier's own exit from holdings in Darwin Airline and, before that, Aer Lingus leaves its European investment strategy in a state of disarray.

Now that Etihad Airways has elected to stop funding Air Berlin, forcing the German carrier to file for assembly, a central question is which parts of the business can continue to operate in the long term.